All conversions (all conv.) is a calculation of all the conversions that your campaigns drive. All conversions include the data in your 'Conversions' column plus conversion actions that you've chosen not to include in your 'Conversions' column. It also includes cross-device conversions, shop visits, certain phone calls and more.
Comparing 'All conversions' to your regular 'Conversions' column can give you a more accurate understanding of how users interact with your business and help you better calculate the effectiveness of your advertising.
Learn more about the 'All conversions' column.